NEW HAVEN — The lab technician accused of killing Yale University student Annie Le is expected to enter a guilty plea and avoid a trial as part of a deal made in the case, one of his attorneys said Tuesday.

Senior Assistant Public Defender Beth A. Merkin said Raymond Clark III will change his not-guilty plea to guilty at a scheduled hearing Thursday in Superior Court. She declined to specify what charge or charges he would plead to or to discuss other terms of the agreement.

"In this case as in any case where there is a plea agreement, you make the decision to do that based on what is in the best interests of the client," Merkin said.

Le, 24, a third-year doctoral student in pharmacology from Placerville, Calif., was reported missing Sept. 8, 2009. For days, local and state investigators and the FBI searched the basement of the Yale Animal Research Center, a research building at the Yale School of Medicine complex where Le was last seen alive. Clark worked at the center and Le did research there.

On Tuesday afternoon, Le's family initially released a statement saying they were relieved to hear about the guilty plea. But Tuesday evening they said they wanted to withhold comment "until it is officially announced by the court.''

"The family is grateful for the support they've received from the community and from law enforcement here and in New Haven," said Kevin Eckery, a spokesman for the family. "The sad fact is that no plea and no sentence will bring Annie back."

Clark's sentencing hearing is tentatively scheduled for June.

Crime 11/2 Years Ago

Police found Le's body stuffed inside a wall at the center on Sept. 13, 2009, the day Le was to be married. The state medical examiner said that Le died of traumatic asphyxiation due to neck compression. The search for Le and the subsequent arrest of Clark attracted widespread media attention.

Officials have not revealed a motive for the slaying, but sources familiar with the investigation have told The Courant that the crime stemmed from a work dispute between Clark and Le.

Court records show that investigators based their arrest of Clark on DNA evidence, a combination of computer records of security cards that showed Clark's movements at the lab on Sept. 8, the day Le was last seen alive, and his attempts to clean up the crime scene.

Clark, 26, of Middletown, is being held at the MacDougall-Walker Correctional Institution in Suffield, with bail set at $3 million. He has pleaded not guilty to murder and felony murder. Each charge carries a punishment of 25 to 60 years in prison.

Last year, an attorney for Le's family raised questions about the school's handling of Le's disappearance and the investigation of her death and said they were considering legal action, possibly against Yale.

Brian King, a New York attorney, said he had been hired by Le's mother, Vivian, who lives in Placerville, Calif. He said he and private investigators were trying to determine answers to questions in the case, including whether Yale did a proper background check on Clark before he was hired.

King could not be reached for comment Tuesday.

Yale spokesman Thomas Conroy said Tuesday that the school was not aware of Clark's plans to change his not-guilty plea. He declined further comment.

According to court records, Le swiped her key card at 10:11 a.m. in a lab room at the research center on Sept. 8, 2009. Clark, who tended the animals there, wasn't far behind, reporting for work at the center 29 minutes later.

At 11:04 a.m., Clark, wearing blue jeans, white shoes and a dark-colored jacket with white stripes, entered the lab where Le was working and remained there for 46 minutes. He signed in as "RC," using a green-ink pen, records state.

Clark was busy at the lab that day, according to key-card activity that shows a person's movement in, out and throughout the center, a state-of-the-art secure building on Amistad Street.

From 10:40 a.m. that morning until 3:45 p.m., Clark went in and out of the lab room where Le was working and another room down the hall 55 times, according to the court documents.

When he left the building that day, Clark was seen wearing different clothes from the ones he entered wearing.

Le, however, was never heard from again.

By 11 p.m. Sept. 8, police were already wondering what happened to Le, who was looking forward to marrying her college sweetheart that Sunday in a lavish Long Island wedding. By all accounts from Le's family and friends, Le was excited about her upcoming wedding. Rumors about her being a runaway bride soon turned into concern about Le's safety.

When Le's key card, as well as video surveillance cameras — which are posted in all of the research center's exits, according to the FBI — showed that Le never left the building, investigators began an all-out search inside the research center, interviewing Le's co-workers and other employees who might have seen her.